Wireless mobile battery

ABSTRACT

A charging device for wirelessly charging an electronic device has a wireless power receiver antenna. The charging device includes a battery having a front surface and a back surface. The charging device has a first antenna comprising a wireless power transmit antenna or a dual-mode antenna. The first antenna is configured to wirelessly transmit power. The charging device has a second antenna. The second antenna includes a wireless power receiver antenna or a dual-mode antenna. The first antenna is configured to wirelessly receive power. The charging device also includes a housing encapsulating the battery, the first antenna, and the second antenna. The housing has a front contact surface opposed to a rear surface, and the contact surface has a coupling portion configured to couple the charging device with the electronic device. The first antenna is closer to the contact surface, and the second antenna is closer to the rear surface.

PRIORITY

This patent application is a continuation of U.S. patent applicationSer. No. 16/531,060, which claims priority from provisional U.S. patentapplication No. 62/714,640, filed Aug. 3, 2018, entitled, “WIRELESSMOBILE BATTERY,” and naming William Vahle and Lukas Scheurer asinventors, the disclosures of which are incorporated herein, in theirentirety, by reference.

This patent application also claims priority from United States designpatent application numbers 29/664,014, filed Sep. 20, 2018, entitled“BATTERY CHARGING DEVICE”, and Ser. No. 29/666,864, filed Oct. 16, 2018,entitled, “BATTERY CHARGING DEVICE,” and naming William Vahle and LukasScheurer as inventors, the disclosures of which are incorporated herein,in their entirety, by reference.

FIELD OF THE INVENTION

Illustrative embodiments of the invention generally relate to a batteryfor charging electronic devices and, more particularly, the illustrativeembodiments relate to wireless mobile charging.

BACKGROUND OF THE INVENTION

Increasingly society has become dependent on electronic devices, such ascell phones and laptops. These devices frequently draw power from aconnected battery that is internal to the housing of the device. Thesebatteries require charging, for example, from a grid-connected powersource.

SUMMARY OF VARIOUS EMBODIMENTS

In accordance with one embodiment of the invention, a method wirelesslycharges an electronic device. The method provides an electronic devicehaving a device antenna configured to receive power wirelessly. Themethod also provides a charging device having a battery having a frontsurface and a back surface. The charging device includes a first antennaon the front surface, and the first antenna includes a wireless powertransmit antenna or a dual-mode antenna. The first antenna is configuredto wirelessly transmit power. The charging device also includes a secondantenna on the back surface, and the second antenna includes a wirelesspower receiver antenna or a dual-mode antenna. The second antenna isconfigured to wirelessly receive power. The charging device furtherincludes an imperforate housing encapsulating the battery, the firstantenna, and the second antenna. The housing has a front contact surfaceand a rear surface. The first antenna is closer to the contact surface,and the second antenna is closer to the rear surface. The method chargesthe electronic device by positioning the charging device relative to theelectronic device such that the first antenna transmits power to theelectronic device antenna.

In some embodiments, the contact surface has an adhesive thereonconfigured to couple the charging device with the electronic device.Additionally, positioning the charging device relative to the electronicdevice comprises coupling the charging device to the electronic device.In some embodiments, the positioning substantially aligns the firstantenna with the device antenna. Among other ways, the charging devicemay be coupled to the electronic device using the adhesive on thecontact surface.

The method may also uncouple the charging device from the electronicdevice. The method may simultaneously charge the charging device from agrid-connected wireless charger as the charging device charges theelectronic device. Additionally, or alternatively, the method maysimultaneously charge a second electronic device having a second deviceantenna by positioning the charging device relative to the secondelectronic device such that the second antenna transmits power to thesecond device antenna. In some embodiments, the housing may be sealedand/or monolithic.

In accordance with yet another embodiment, a charging device forwirelessly charging an electronic device has a wireless power receiverantenna. The charging device includes a battery having a front surfaceand a back surface. The charging device also has a first antennacomprising a wireless power transmit antenna or a dual-mode antenna. Thefirst antenna is configured to wirelessly transmit power. The chargingdevice also has a second antenna. The second antenna includes a wirelesspower receiver antenna or a dual-mode antenna. The first antenna isconfigured to wirelessly receive power. The charging device alsoincludes a housing encapsulating the battery, the first antenna, and thesecond antenna. The housing has a front contact surface opposed to arear surface, and the contact surface has an adhesive thereon configuredto couple the charging device with the electronic device. The firstantenna is closer to the contact surface, and the second antenna iscloser to the rear surface.

In some embodiments, the rear surface of the housing is configured tocouple with a second electronic device. The housing may also behermetically sealed and/or monolithic. The housing may have a taperedtransition surface between the contact surface and the rear surface.Additionally, in some embodiments, a display may protrude from thehousing. Among other things, the display may include LEDs. The housingmay also encapsulate a heat pipe coupled with the battery.

Although described as wirelessly receiving power, the second antenna mayalso be configured to wirelessly transmit power. Additionally, the firstantenna may also be configured to wirelessly receive power. Furthermore,some embodiments may have two antennas, in which at least one is dualmode. Some other embodiments may have a single antenna that is dualmode.

In accordance with yet another embodiment, a system includes anelectronic device having a device antenna configured to receive powerwirelessly. The system also includes a charging device having a batterywith a front surface and a back surface. The charging device includes afirst antenna and a second antenna. The first antenna includes awireless power transmit antenna or a dual-mode antenna, and isconfigured to wirelessly transmit power. The includes a wireless powerreceiver antenna or a dual-mode antenna, and is configured to wirelesslyreceive power. The charging device includes a housing encapsulating thebattery, the first antenna, and the second antenna. The housing has afront contact surface opposed to a rear surface. The contact surface mayhave an electronic device coupling portion thereon configured to couplethe charging device with the electronic device. The first antenna may becloser to the contact surface, and the second antenna may be closer tothe rear surface.

The system may further include a grid-powered wireless chargerconfigured to charge the charging device. The housing of the chargingdevice may be hermetically sealed. Furthermore, the contact surface ofthe housing may have adhesive thereon.

Illustrative embodiments of the invention are implemented as a computerprogram product having a computer usable medium with computer readableprogram code thereon. The computer readable code may be read andutilized by a computer system in accordance with conventional processes.

BRIEF DESCRIPTION OF THE DRAWINGS

Those skilled in the art should more fully appreciate advantages ofvarious embodiments of the invention from the following “Description ofIllustrative Embodiments,” discussed with reference to the drawingssummarized immediately below.

FIG. 1 schematically shows a perspective view of an electronic devicecoupled with a mobile charger in accordance with illustrativeembodiments of the invention.

FIG. 2 schematically shows a side view of the electronic device coupledwith the mobile charger in accordance with illustrative embodiments ofthe invention.

FIG. 3 schematically shows a perspective view of an arrangement of agrid powered wireless charger, the electronic device, and the mobilecharger for storing and receiving power in accordance with illustrativeembodiments of the invention.

FIG. 4 schematically shows an exploded perspective view of the chargerin in accordance with illustrative embodiments of the invention.

FIG. 5 is a block diagram of a system in accordance with an embodiment.

FIG. 6 schematically shows a perspective view of the electronic deviceand the mobile charger in accordance with illustrative embodiments ofthe invention.

FIG. 7 schematically shows alternative configurations for placement ofinternal components of the mobile charger in accordance withillustrative embodiments of the invention.

FIG. 8 schematically shows a side view of an electronic device, a mobilecharger, and a second electronic device in accordance with illustrativeembodiments of the invention.

FIG. 9 schematically shows coupling the mobile charger to an electronicdevice in accordance with illustrative embodiments of the invention.

FIG. 10 shows a process of charging the electronic device using thecharger in accordance with illustrative embodiments of the invention.

DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS

In illustrative embodiments, a charging device (referred to as“charger”) has a battery with two antennae that allow for thesimultaneous receiving and transmitting of power wirelessly. One of theantennas may transmit power wirelessly, and the other antenna mayreceive power wirelessly. Because the battery may receive and transmitpower wirelessly, it may be encapsulated within a monolithic and/orsealed (e.g., hermetically) housing without any need for externalelectromechanical connections. Without the ability to both receive andtransmit power wirelessly, the charger could not be monolithic,overmolded, and/or sealed without an electromechanical connection. Thisis because a sealed housing that can receive power wirelessly wouldresult in a charged battery that is otherwise unusable without thedestruction of the housing. Alternatively, a sealed housing that canonly transmit power wirelessly would result in a single use charge.Accordingly, illustrative embodiments enable the functional and repeateduse of a mobile wireless charger in a sealed and/or monolithic housing.

Illustrative embodiments of the charger provide a number of advantagesin many situations, including: applications where contamination and/orenvironmental hazards may prevent usable and/or reliableelectromechanical connections, applications where a spark (e.g., createdby an electrical connection) may be undesirable, and/or waterproofapplications. Additionally, in some embodiments, the housing of thecharger may have an adhesive that allows the charger to physicallycouple to another device. To that end, the wireless transmit antenna maybe positioned to face a surface of the housing having the adhesive.Accordingly, the charger may wirelessly transmit power to another deviceas they are coupled. Simultaneously, the wireless charger may itself becharged wirelessly from another device (such as a grid-connectedcharger). Details of illustrative embodiments are discussed below.

FIG. 1 schematically shows a perspective view of an electronic device 40coupled with a mobile charger 50 in accordance with illustrativeembodiments of the invention. Most mobile power solutions currentlyavailable and currently in use connect to the target powered device 40using cables/connectors (not shown). However, cables/connectors presenta number of disadvantages:

(a) are subject to connector fatigue & fouling (wearing out & gettingdirty),

(b) fray and fall apart,

(c) connectors are not designed to exclude water or corrosivesubstances,

(d) physically snap/break off, often damaging the device 40,

(e) dramatically hamper the form factor, ergonomics and usability of themobile electronic device 40,

(f) impair the portability of the device 40 receiving power.

Mobile power solutions that provide power to connected devices 40 viaone or more cables/connectors may often themselves embody a seconddevice for the user to physically manage, and may be cumbersome, whileconnecting cables and mechanical accessories (e.g., bulky mechanicalconnections, electromechanical connectors, overly thick housings,USB-to-device cables) create an unwieldy and undesirable userexperience.

Additionally, many mobile power solutions enclose a majority of thereceiving device 40 (e.g., a mobile phone charging case) and may hamperthe usability of the physical form factor of the device 40. Theavailability of power in mobile electronics is a constant, criticalchallenge, and an ongoing focus in the design of mobile electronics. Byproviding more power to the user's device 40, the user may make more useof the device 40 without running out of battery power.

Illustrative embodiments of the invention provide a wireless charger 50having a number of advantages. For example, illustrative embodimentsprovide a robust wireless charger 50 with no need for electromechanicalconnectors. Instead, the charger 50 uses inductive coils for wirelesspower transmission and reception. Furthermore, illustrative embodimentsoffer protection from corrosion and fouling to which mechanical powerconnections are particularly susceptible.

Further advantages of illustrative embodiments include that no tangibleexternal connection is required for proper operation, allowing forsuperior protection from liquid infiltration, electrostatic discharge,dust infiltration, corrosion, contact fatigue, corrosive materials,gaseous infiltration, electrostatic discharge, exposure to vacuum orextreme atmospheric pressures, explosive gases etc. Accordingly, thecharger 50 may be imperforate, and/or have a monolithic and/or sealedhousing 55. Additionally, such a charger 50 may be universallyattachable to receiving mobile devices 40 by means of a reusableadhesive film, or other technologies such as magnets or simplemechanical connections.

As described previously, the charger 50 may provide power to mobileelectronics devices 40 such as, for example, mobile phones and tablets.The charger 50 may also provide power to tools, measurement equipment,sensors, communication devices, lights, and/or any mobile device 40which can receive power or be made to receive power through means ofwireless power transfer. The charger 50 may also be utilized to providepower to a device 40 which may be considered stationary.

As shown in FIG. 1 , electronic device 40 may have a generallyrectangular body 45 and the charger 50 may have a housing 55. Thehousing 55 may be dimensioned so as to form an ergonomic whole whenaffixed to the electronic device 40, such as by dimensioning the housing55 in accordance with the dimensions of the electronic device body 45.Various examples of the shape of the housing 55 may be found, forexample, in U.S. design patent applications 29/664,014 and 29/666,864,which are incorporated herein by reference in their entireties.

The charger 50 may include components for communicating and/ordisplaying information to the user regarding the state of the charger 50(e.g., battery level remaining). For example, the charger 50 may includea display 68, such as LEDs 67, which may be used to communicateinformation such as state of charge, error conditions, deviceconnectivity etc. Illustrative embodiments may also include a graphicdisplay, touchscreen display, two dimensional LED matrix, threedimensional LED matrix, and/or electromechanical indicator. It should beunderstood that the LEDs 67 are merely illustrative. The charger 50 mayalso include one or more user interfaces/buttons 66 that are used tocontrol the state of the charger 50. In some embodiments, the button 66may be a capacitive touch button.

FIG. 1 illustrates one embodiment of a single pushbutton 66.Manipulation of the button 66 may cause the charger 50 to change states,such as from an OFF state to an ON state and vice-versa. Additionally,manipulation of the button may display or change operating parameters,such as to activate a secondary transmitter, switch the operating modeof an antenna, and/or activate a function of the charger 50. Theembodiment illustrated in FIG. 1 is illustrative of one of many possibleconfigurations.

The charger 50 may have a wireless communication interface, e.g., WiFi,Bluetooth, etc., to allow for communication with the charger system suchas by a smartphone app, e.g., for configuring or controlling the charger50. For example, the battery 102 may perform charging differently basedon the type of device 40 (e.g., smartphone) to which it is connected, orbased on the level of charge of the device 40 to which it is connected,and such information could be learned by the charger 50 via a wirelessconnection to the device or smartphone app. For example, the charger 40may include its own “smart” charging operation modes to conserve its ownbattery power, e.g., switching to a “trickle” charge when the connecteddevice 40 is above a predetermined charge, thereby saving battery lifeon the charger 50. In some embodiments, the battery level of theconnected device 40 can be detected via the antenna and the chargingmode may be controlled accordingly. In some embodiments, the wirelesscommunication interface may be accessed/controlled through the display68 or button 66.

FIG. 2 schematically shows a side view of the electronic device 40coupled with the mobile charger 50 in accordance with illustrativeembodiments of the invention. The charger 50 of FIG. 2 has analternative housing 55, but may otherwise be identical to the charger 50of FIG. 1 . As shown in FIG. 2 , the housing 55 may have one or moretapered surfaces 59 from a front surface 56 configured to contact thedevice 40 (also referred to as contact surface 56) to an opposed rearsurface 57. The tapered surface 59 provides the advantage of reducingcontact points and/or friction that may otherwise dislodge the charger50 from device 40 (e.g., when removed from a user's pocket).

The charger 50 may be coupled to the electronic device 40, for example,by a coupling portion 81 (e.g., reusable adhesive film 81).Additionally, or alternatively, the charger 50 may also be coupled tothe electronic device 40 using a coupling portion, for example, magnets,suction cups, hook and loop fasteners, etc. Alternative configurationsof means for coupling the charger 50 to a mobile electronic device 40are illustrated in FIG. 9 .

In illustrative embodiments, the housing 55 may be shaped and/ordimensioned differently than shown. The examples shown in the figuresare merely illustrative. For example, the housing 55 may be dimensionedto correspond with the device 40, so as to form a whole which is morephysically compatible with the device 40. Among other things, theelectronic device 40 may be a smartphone, a portable media player, atablet, and/or a headphone case. Further examples may include portablemeasurement equipment, portable or fixed sensor devices, communicationdevices, flashlights or electrically powered tools. The housing 55 mayhave different dimensioning, may be thinner or thicker, may have aconvoluted exterior, and may have a design whose ergonomics and/ordimensioning correspond to an electronic device 40 with which it isprimarily intended or marketed to be used. For example, the charger 50may be dimensioned different for an iPhone as opposed to an iPad. Theexample of FIG. 1 is merely illustrative.

As an example of dimensions that some embodiments of the charger 50 mayhave, the housing 55 may have a length of about 103 mm, a width of about57 mm, and a thickness of about 9 mm at its thickest point. The charger50 with the above described dimensions may have, for example, a battery102 with a capacity of about 2,700 mAh to about 3,100 mAh. In someembodiments, the thickness of the housing 55 may be between about 5 mmand about 12 mm. In some embodiments, the width may be between about 30mm and about 100 mm. In some embodiments, the length may be betweenabout 50 mm and 120 mm.

The electronic device 40 may contain an antenna or antennae for thereception of power via means of wireless power transfer (e.g., see FIG.4 ). In illustrative embodiments, the housing 55 is dimensioned suchthat when it is coupled to the electronic device 45 (e.g., a frontsurface 56 contacts the body 45), the receiving antenna in the body 45is positioned and aligned with respect to the transmitting antenna inbody 55 for efficient wireless transfer of power.

Wireless transfer of power may be achieved by one or more antennae. Theantenna has a segment or segments of material formed in a manner suchthat its electrical and mechanical properties are useful in thetransmission of power to or from one or more other antennae.Additionally, any antennae in the charger 50 and/or device 40 may beutilized for the transmission or receiving of power at different times,in different embodiments or in different modes of operation.

Additionally, the antenna may consist of multiple sub-segments which maythemselves be classifiable as antennae, but which together act inconcert to form a single functional block, such as in a phased arraysystem. Additionally, such antennae acting in concert may also act inmultiple modes concurrently or discretely, for the potential use of thearray to function in both receive and transmit states, such as through atime division multiplexed system. In some embodiments, antennacomponents and designs used in the charger 50 may be off-the-shelf andcommercially available, particularly as concerns compliance with anypublished standard for wireless power transfer. Furthermore, antennaeused in the wireless transfer of power may also communicate informationpertinent to the transfer of power.

In some embodiments, one or more antennae may be constructed from woundcopper wire (e.g., multi-stranded, Litz, dimensionally braided, solid),printed circuit boards, flexible printed circuit boards, stamped metal,and/or any configuration of conductor, semi-conductor, dielectric,insulator, ferrite etc. that is utilized within the charger 50 as anantenna for the purposes of wireless power transfer. The antenna neednot necessarily be composed of only a single element, but may alsoconsist of multiple active or passive elements which work independentlyor in unison to achieve the wireless transfer of power. Additionally,consideration of a single antenna or cooperative antennae may alsoinclude various operating states wherein discrete elements function inconcert or independently in configurations determined to be mosteffective for the wireless transfer of power.

FIG. 3 schematically shows a perspective view of an arrangement of agrid powered wireless charger 82, the electronic device 40, and themobile charger 50 for storing and receiving power in accordance withillustrative embodiments of the invention. The housing 55 may contain(e.g., encapsulate) a battery 102, such as a prismatic battery cell. Thebattery is an energy storage medium including, e.g., lithium basedbatteries, nickel based batteries, carbon based batteries, aluminumbatteries, supercapacitor-type cells, or any medium for the storage andrelease of electrical power.

The charger 50 may include a means of affixing the housing 55 to themobile electronic device 40. The charger 50 may include any suitablenumber of antennae (e.g., one or more, two or more, three or more, fouror more, etc.), which may be utilized for any number of purposes,including the transmission and/or reception of power. The antennaewithin device 40 may be of many various types, (e.g., distributed ormulti-part antennae, consisting of either whole or parts of structuralelements; flexible circuit board antennae; coiled wire or film antennae,etc.).

In illustrative embodiments, the charger 50 contains twoantennae—antenna 61 and antenna 105 (underside, not visible in FIG. 3 ).The charger 50 is depicted in a partly exploded view, in a configurationin which the charger 50 is receiving power wirelessly from agrid-powered Qi wireless charger 82, e.g., via bottom antenna 105. Thegrid-powered charger 82 represents an external “fixed source”. The fixedsource charger 82 may be a source of power external to the charger 50(e.g., provided by the user) that is intended to wirelessly providepower to the charger 50, or directly to the end device 40. Such a sourcewould typically be driven by grid power, and is described here as a“fixed-source”.

In some embodiments, the antenna 61 is a wireless transmit antenna andthe antenna 105 is a wireless receive antenna. Furthermore, either, orboth, of the antennas 61 and 105 may be wireless dual-mode antennascapable of alternating between receiving power wirelessly andtransmitting power wirelessly. Additionally, or alternatively, thecharger 50 may include antennas that are dual-mode antennas.Furthermore, the charger may include more than two antennas 61, 105, forexample, two antennas on each side of the battery 102.

Depending on the rate at which the mobile electronic device 40 receivespower, the present state of charge of the device 40, the current stateof charge of the charger 55, and other ancillary factors like device 40temperature etc., a number of different states are possible. Enumeratedbelow are possible states, which are provided for illustrative purposesand are not intended to be exhaustive list of possible device states,but rather is intended to facilitate discussion of illustrativeembodiments:

a) In illustrative embodiments where a mobile electronic device 40accepts power at a rate that is less than the available power assupplied by an external “fixed-source” charger 82, the charger 50 mayreceive and store this excess power in its internal battery 102. Whilesupplying power to the mobile electronic device 40 at the full rate itwill accept, the charger's 50 internal battery 102 may increase itsstate of charge simultaneously. Thus, the rate at which power is storedin the combined mobile form factor may be increased.

b) In illustrative embodiments where a mobile electronic device 40 isaccepting power at a rate equivalent to or greater than the rate atwhich power is available from an external “fixed-source” 82, the charger50 may pass power received from the external source through itself andto the mobile electronic device 40 via means of wireless powertransmission, while not simultaneously charging the internal battery102. This may, for example, be because the charger's 50 internal battery102 is nominally at a 0% state of charge and no battery power isavailable to supplement the power received from the external source, orbecause the state of charge of the charger's 50 internal battery 102 isnominally at 100% and current drawn by the mobile electronic device 40is too small to warrant drawing down the charger's internal battery 102(e.g., device 40 is connected to the charger 50, but is drawing only astandby-level of power).

c) In illustrative embodiments where the mobile electronic device 40 isaccepting power at a rate which is greater than the rate at which poweris available from an external “fixed-source” 82, the charger 50 may passthe external power input through itself from its internal receivingcircuitry to transmission circuitry, and supplementally supply power tothe transmission circuitry up to the maximum rate which the charger's 50internal battery allows, or up to the rate at which the end-device 40will receive.

d) In illustrative embodiments where the charger 50 is coupled to themobile electronic device 40 and no external “fixed-source” 82 ispresent, charger 50 may supply power from its internal battery 102 tothe mobile electronic device 40.

FIG. 4 schematically shows an exploded perspective view of the charger50 in accordance with illustrative embodiments of the invention. Asdescribed previously, the charger 50 may contain internal electronics.For example, the charger 50 may include circuitry that facilitates thewireless transfer of power via illustrative antenna 61 and a secondantenna 105 underneath. The internal electronics may contain elementssuch as circuits configured to condition and make useful power receivedwireless (“receiving circuitry”); they may contain circuits designed tosupply electrical power to an antenna for the purposes of transmissionto another device 40 (“transmitting circuitry”); they may containcircuits useful for charging a battery 102 internal to the charger 50;they may contain electronics which make useful power which is drawn froman internal storage source such as a battery 102. Additionally, internalelectronics may also contain circuits to perform various functions, suchas to control a display (e.g., to provide operational and chargingstatus and/or statistics), to cause the charger 50 to change states(e.g., to switch from an OFF state to an ON state and vice-versa), tosense internal and external parameters and circumstances (e.g., thepresence of a receiver and/or transmitter, human handling of charger 50,charger 50 temperature etc.), to activate functions based on variouscharger 50 state stimuli, to change/display operating parameters, toactivate a secondary transmitter, and/or to switch the operating mode ofan antenna, such as to activate other charger 50 function(s). In someembodiments, the mode of the dual-mode antenna may be controlled.

The housing 55 may be formed by overmolding, whereby the componentsinternal to the charger 50 are placed in an apparatus which flows apolymer plastic or other material around the components in one or moreoperations in order to encapsulate the internal components of thecharger 50. Overmolding here is intended to include processes similar toovermolding such as potting, whereby the charger 50 is placed in a shellhousing and material is deposited into the shell around the componentsthus encapsulating the charger 50. Accordingly, in some embodiments, thecharger 50 and internal components are monolithic (e.g., a single piecewith no superfluous internal cavities and/or no access to internalregions of the charger 50). The overmolding process may also beconducted in a manner so as to form and/or make allowance for acomponent that directs light from an internal light source to theexterior of the charger 50 for purposes of the display of information(e.g., see display 68 in FIG. 1 ); allowances for and/or the presence ofsuch a component may not necessarily obviate description of the charger50 as imperforate and/or monolithic.

Other assembly methods include casting, traditional encapsulation,assembly in a housing with additional encapsulant, injection molding,and simple assembly within the housing 55 (e.g., the housing 55 may beconstructed of plastic, metal, composite materials, glass etc., and maybe fastened with threaded fasteners, glue/epoxy, ultrasonic welding,and/or other means known to those skilled in the art).

Although the housing 55 is shown as two parts 55 a and 55 b, it shouldbe understood that this is merely illustrative and not intended to limitvarious embodiments of the invention. For example, using the overmoldingprocess described, these two pieces 55 a and 55 b would form a singlepiece. However, some other embodiments may form the housing 55 from twoor more pieces 55 a and 55 b as shown.

The overmolding or other manufacturing process of the housing 55 is mayalso account for other components that are exposed in illustrativeembodiments. The components may include component(s) that are intendedfor use as user input such as the pushbutton 66 represented in FIG. 1 .Such an input may also include constructions whereby the user may changethe state of the charger 50 by means other than actuation of anelectromechanical component, such as capacitive sensing circuits,resistive touch sensing circuits or other components that allow the userto affect input to the control electronics. These circuits may becontained within the housing 55 of the charger 50. They may also beconstructed by being affixed on the exterior of the charger 50.Illustrative embodiments of the charger 50 include an electromechanicalpushbutton contained within the housing 55, around which a housing isconstructed using overmolding or potting techniques.

The housing 55 may be constructed by molding polymer around internalcomponents (e.g., antennae, circuit boards, batteries, light pipes etc.)thus producing complete encapsulation of the internal components of thecharger 50. Such a manufacturing process may be accomplished in multiplesteps and with many different materials. The housing 55 manufactured bysuch methods may have an advantage over other processes in the form of adecreased minimum suitable wall thickness, and thus a reduced overallsize. Such a manufacturing process may also incorporate materials withinthe encapsulant material that are intended to improve the thermalmanagement characteristics of the charger 50 (inf. thermal managementmaterials) through their heat absorption, retention, release,distribution and dissipation characteristics. Manufacturing utilizingthis technique may yield a charger 50 whose usefulness is increased byvirtue of one or more of the following benefits: decreased size,decreased cost, increased manufacturing yield, more suitable heatdissipation, increased resistance to external environmental elements(e.g., corrosion, contaminant infiltration, electrostatic dischargedamage etc.), improved cross-contamination resistance (e.g., more easilysterilized), increased tolerance of deformation, torsional force,crushing, and/or resistance to puncture or prying.

As described herein, illustrative embodiments provide the advantage thatthe housing 55 may be imperforate (i.e., the housing 55 does not haveany input ports for electromechanical connectors). The imperforatehousing 55 lacks the normal opening for an electromechanical connectiongenerally seen for electronic devices 40. In some embodiments, thecharger 50 may not be imperforate, and thus, may have an opening for aninterface in the housing 55 (e.g., USB-type, Apple Lightning). However,in some embodiments, the housing 55 is imperforate and does not have theopening for interfaces (e.g., USB-type, Apple Lightning). Thus, thecharger 50 may not use an electromechanical connection to charge otherdevices 40 or to be charged. Accordingly, in some embodiments, anotheradvantage is that the charger 50 may charge a device 40 without usingone of its electromechanical connections (e.g., charging a smartphoneusing an electromechanical connection in some instances prevents theuser from plugging in audio headphones into the smartphone).

In the context of this description and accompanying claims, animperforate housing 55 lacks any of the physical interfaces generallyfound on electronic devices 40 for receiving or transmitting electricalpower, e.g., a power receptacle, a USB port, etc., and generally alsolacks any other physical openings that could allow moisture or debrisinto the charger 50, e.g., openings for ventilation or audio, othercommunication ports, etc.

Additionally, the charger 50 may also exhibit increased resistance toharsh environments as a result of robust sealing (e.g., as accomplishedvia molding). Such improvements may be further utilized by theelimination of any external orifice on the charger 50, thus preventingthe infiltration of environmental hazards harmful to its operation orwhich may damage the useful lifespan of the charger 50. Environmentalhazards include corrosion, contact fouling/fatigue, water infiltration,dust infiltration, corrosive materials, gases or liquids infiltration,electrostatic discharge, exposure to vacuum or extreme atmosphericpressures, etc. Additionally, utilization of manufacturing techniquesdescribed herein may allow the manufacturer of the charger 50 toreconfigure the form factor of the housing, such as to allow for theinclusion of a larger battery 102 and/or to optimize ergonomic couplingwith mobile electronic device 40, at a low cost, as limited changes maybe made to the external form factor of the charger 50 without mandatingadditional changes to any enclosed electronics.

The charger 50 may also contain ferritic/ferromagnetic material thatprovide magnetic fixturing of the charger 50 to devices 40 with whichthe user intends to conduct a wireless transfer of power. Additionally,such ferromagnetic material may provide for magnetic fixturing of thecharger 50 to an external fixturing mechanism for receiving ortransmitting power (e.g., a car dashboard charger). The encapsulantmaterial may also be chosen or modified to achieve desirable dielectricproperties to enhance the process of wireless transfer of power, fireresistance, weight, durability, ease of manufacture, thermalcharacteristics, etc. Molding as referenced here may refer to a numberof techniques such as molding, potting, overmolding, casting,encapsulation, and assembly of pre-molded parts with additionalencapsulant. The charger 50 may include a heat pipe 71, which may beconstructed of a thermally conductive material such as aluminum orcopper. The heat pipe 71 manages heat through absorption, retention,release, distribution and dissipation. The heat pipe 71 may include amaterial included to transfer heat away from the point where heat isgenerated. The heat pipe 71 may be textured and dimensioned to increaseits surface area, to facilitate heat transfer. The enclosure of thecharger 50 may be connected to the heat pipe 71, for the purposes ofdissipating to the surrounding environment heat generated during charger50 operation.

The heat pipe 71 may also serve an electromagnetic shielding purpose,such as by the ferrite plate common in wireless power transfer antennae.The illustrative heat pipe 71 is dimensioned and placed within thehousing 55 such that it draws heat from the antennae(s) 61,105, circuitboard(s) 62, and battery 102, and distributes it more evenly within thehousing 55. Accordingly, the heat pipe 71 may eliminate thermalgradients and allow the charger 50 to operate more efficiently. Such aheat pipe 71 may have a surface treatment, such as bead blasting, anddimensioned features, such as cooling fins, which increase the surfacearea of the component in order to facilitate a greater transfer of heat.The heat pipe 71 may be featured 75 so as to be bonded to the housing 55to facilitate the transfer of heat for more ready dissipation to theoutside environment.

Additionally, or alternatively, the housing 55 may include materialwhich serves to absorb, retain, release, transfer and dissipate heat.Such material may be placed so as to manage the flow of heat within thecharger 50, particularly during operation of the charger 50 and mostparticularly during intensive phases of operation, such that heat isdrawn away from sensitive components, such as integrated circuits andbattery components, and retained, distributed, released and/ordissipated. Such materials may include materials called phase changematerials or other existing or novel materials which achieve the abovedescribed characteristics. Such attention to thermal management mayprolong the useful lifespan of the charger 50. Such thermal managementmay also allow for the transfer of greater amounts of power withoutdamaging the charger 50 or its components, thus improving performanceand user comfort.

FIG. 5 is a block diagram of a system 100 in accordance withillustrative embodiments of the invention. As described previously, thebattery 102 within the charger 50 may provide electrical power fortransmission to an external device 40 through means of wireless powertransfer. The power supplied to an external device 40 by means ofwireless power transfer may supplement internal battery power in theexternal device 40. Power may be received by the charger 50, through oneor more antenna 105 located on or within the housing 55, and may bepassed through the charger 50 and by wireless power transmission (e.g.,via transmission circuit and antenna 61) provide power to the externaldevice 40. Power received from an external source may be stored in theenclosed battery 102.

Each of the above-described components may be operatively connected byany conventional interconnect mechanism. FIG. 5 simply shows a buscommunicating some of the components. Those skilled in the art shouldunderstand that this generalized representation can be modified toinclude other conventional direct or indirect connections. Accordingly,discussion of a bus is not intended to limit various embodiments.

Indeed, it should be noted that FIG. 5 only schematically shows each ofthese components. Those skilled in the art should understand that eachof these components can be implemented in a variety of conventionalmanners, such as by using hardware, software, or a combination ofhardware and software, across one or more other functional components.For example, the electronics in the charger 50 may be implemented usingone or more microprocessors executing firmware. As another example, thereceiver circuitry and/or transmitted circuitry may be implemented usingone or more application specific integrated circuits (i.e., “ASICs”) andrelated software (e.g., control software), or a combination of ASICs,discrete electronic components (e.g., transistors, logic gates), and/ormicroprocessors. Accordingly, the representation of the components in asingle box of FIG. 5 is for simplicity purposes only. In fact, in someembodiments, the circuitry of FIG. 5 may be distributed across aplurality of circuit boards—not necessarily within the same housing orchassis. Furthermore, some circuitry may be duplicated across circuitboards in order to minimize the number of wiring interconnectsnecessary. Additionally, in some embodiments, components shown asseparate (such as Charger Device Control 69 and the Radio DataCommunication 166 in FIG. 5 ) may be replaced by a single component.Furthermore, certain components and sub-components in FIG. 5 areoptional. For example, some embodiments may not use the Radio DataCommunication 166.

It should be reiterated that the representation of FIG. 5 is asignificantly simplified representation of the charger electronics.Those skilled in the art should understand that the charger 50 may haveother physical and functional components, such as power management andconditioning modules, DC-DC converters, bypass capacitors, ESDprotection components, and reverse polarity protection diodes.Accordingly, this discussion is not intended to suggest that FIG. 5represents all of the elements of the charger 50 electronics.

FIG. 6 schematically shows a perspective view of the electronic device40 and the mobile charger 50 in accordance with illustrative embodimentsof the invention. The charger 50 charges the mobile electronic device 40(e.g., while coupled to the electronic device 40). Notably, as opposedto FIG. 3 , the charger 50 is no longer receiving power from a gridconnected fixed wireless-power source 82. Still, the charger 50 providespower to the device 40 from what is stored in the battery 102.

In illustrative embodiments, the antenna 61 is positioned on an oppositeside of the battery 102 from the antenna 105. Preferably, the antenna 61is configured to wirelessly transmit power, while the antenna 105 isconfigured to wirelessly receive power. Furthermore, in illustrativeembodiments, the antenna 61 is configured to transmit power ispositioned closest to the front surface 56 (also referred to as the“contact surface 56”) of the housing 55. As described previously, thehousing 55 may include means for coupling the charger 50 to the device40 (such as adhesive film 81) on the contact surface. Thus, the charger50 is configured to charge the device 40 when the two are coupled and/orin close proximity (e.g., if the device 40 is placed on top of contactsurface 56 of charger 50 without the use of adhesive or other coupling).Although not shown in this figure, this configuration further providesfor the simultaneous receipt of power via the antenna 105 configured towireless receive power, as the device 40 is charged by the charger 50.The inventors discovered that this arrangement provides advantages suchas allowing for simultaneous charging and/or flow through of power froma grid connected fixed source 82 (or other power source), to the charger50, and ultimately to the device 40. Additionally, many users leavetheir device 40 and/or charger 50 charging overnight on a grid connectedwireless charging source. Accordingly, both the charger 50 and thedevice 40 may become fully charged without the need for additionalaction by the user.

Furthermore, the inventors discovered that the wireless receive/wirelesstransmit antennae configuration of illustrative embodiments providescertain advantages, including that the housing 55 may be monolithicand/or sealed. This provides the advantage that the charger 50 may bewashable (e.g., using water). Additionally, the charger 50 may be usedin applications where environmental hazards may render electromechanicalconnections undesirable.

While some embodiments are described as having a monolithic and/orsealed housing 55, in some embodiments the charger 50 may also make useof a wired, electromechanical connection (e.g., microUSB, USB-C) for thepurposes of receiving power from or providing power to externallyconnected devices 40, 40 b.

Furthermore, while some embodiments are described as having a pluralityof antennas 60, 105, it should be understood that some other embodimentsmay have a single antenna 60, such as a single dual-mode antenna 60 or asingle transmit antenna 60. Accordingly, the dual mode antenna 60 may beused to receive power in a receive mode, and may then transmit power ina transmit mode. In embodiments that have a single transmit antenna 60,they may include an electromechanical connection for receiving power andcharging the internal battery 102. Illustrative embodiments having anelectromechanical connection for charging the battery may not beconsidered imperforate.

FIG. 7 schematically shows alternative configurations for placement ofinternal components of the mobile charger 50 in accordance withillustrative embodiments of the invention. Alternative positions ofcircuit boards 62 within the housing 55.

FIG. 8 schematically shows a side view of the electronic device 40, themobile charger 50, and a second electronic device 40 b in accordancewith illustrative embodiments of the invention. Specifically, FIG. 8illustrates the charger 50 in a mode of operation whereby two mobileelectronic devices 40 and 40 b are charged simultaneously. Charger 50 iscoupled to the additional portable electronic device 40 b (e.g., viareusable adhesive film 58). In this case, both antenna 61, 105 would beplaced in Tx mode to transfer power from the battery to both devices 40,40 b. Means of coupling the charger 50 to a second portable electronicdevice 48, third portable electronic device, fourth portable electronicdevice etc. are not intended to be limited to reusable adhesive film,and are intended to include other means such as those enumeratedelsewhere in this disclosure such as magnetics, mechanical means, hookand loop fasteners etc.

FIG. 9 schematically shows alternative embodiments of adhesive forcoupling the charger 50 to the electronic device 40 in accordance withillustrative embodiments of the invention. The housing 55 features ameans of affixing the charger 50 to a portable electronic device 40 forthe wireless transfer of power. Coupling the charger 50 to a mobileelectronic device 40 by removable, refixturable, reusable meansincreases the utility of the charger 50. This provides the advantage ofallowing the charger 50 to couple with receiving devices 40, 40 bwithout the complication of device-specific cases or mount points. Thecharger 50 may have a form factor which is not specificallycomplementary to any one model of electronic device 40, and anembodiment of such a form factor as is illustrated in FIG. 8 . Thecharger 50 may be useful across many varying models of devices 40, andmay be readily reaffixed by the user at will to any number of othercompatible electronic devices which may receive power by wireless means.This would allow the user to, for example, affix the charger 50 to amobile electronic device 40 belonging to a friend, acquaintance,customer, student etc. as the need arises. Examples of how the userexperiences increased utility include the ability to remove the charger50 when the user desires a smaller form factor for the portableelectronic device 40, when the user desires to exchange the device 50for a separate unit which has a different state of charge, when the userdesires to remove the charger 50 for charging while not affixed to theportable electronic device 40, or any number of scenarios in which theuser desires to reconfigure the combination of device(s) 40, 40 b,charger(s) 50, mounting devices etc. Additionally, the charger 50 may beused with any device 40 that includes compatible means of wireless powertransfer. This allows the charger 50 to charge various different devices40 intended to receive power that may not otherwise share compatiblecharging standards (e.g., Apple iPhone Lightning v.s. Samsung microUSB),obviating the need to carry additional equipment necessary to charge arange of devices 40.

The charger 50 may be affixed to the device 40 which the user intends toreceive power from or provide power to by means of a reusable adhesivefilm. Such an adhesive film may be dimensioned according to the device40 or devices intended to receive power. The film 81 may be affixed tothe charger 50 via permanent adhesive film, or it may also be affixed byother common means of permanent fixturing. The film 81 may be adhered tothe charger 50 via a reusable adhesive film. The reusable adhesive film81 may allow the user to affix the charger 50 to a device 40 or devicestransmitting or receiving power at will and repeatably. The reusableadhesive film may allow the user of the charger 50 to remove the charger50 from the device 40 or devices receiving power at will. The reusableadhesive film may be constructed from a polymer material, for examplepolyurethane, vinyl or silicone. The reusable adhesive film may utilize“micro suction technology”. The reusable adhesive film also may usereusable adhesive film known as “gecko tape”. The reusable adhesive filmmay be maintained by rinsing the film in water or solvent. The reusableadhesive film may be maintained by rinsing the film in water or solvent,with or without the aid of detergent. Additionally, or alternatively,the charger 50 may be affixed to an end-device or devices by more commonmeans such as magnets, hook and loop, mechanical interlock, springconnection, press-fit, various configurations of one or more suctioncups, snap-fit, elastic, a mechanical connection etc.

FIG. 10 shows a process 1000 of charging the electronic device 40 usingthe charger 50 in accordance with illustrative embodiments of theinvention. It is should be noted that this process can be a simplifiedversion of a more complex process of charging the electronic device 40.As such, the process may have additional steps that are not discussed.In addition, some steps may be optional, performed in a different order,or in parallel with each other. Accordingly, discussion of this processis illustrative and not intended to limit various embodiments of theinvention.

The process 1000 begins at step 1002, which positions the charger 50 ona wireless charger 82. For example, a user may position the charger 50on the wireless charger 82 so that the charger 50 may wirelessly receiveand store power. The charger 50 may be positioned on the wirelesscharger 82 while it is coupled to another device 40.

The process then proceeds to step 1004, which wirelessly charges thecharger 50. The next step 1006 in the process removes the charger 50from the wireless charger 82. A user may take the charger 50 with them,and accordingly, the user has a mobile wireless charger 50 that may beused to charge a device 40 on the go when necessary. At step 1008, thecharger 50 is positioned on the device 40 and provides power to theelectronic device 40. As described previously, the device 40 may be amobile phone, tablet, and/or power tool that is capable of receivingpower wirelessly. The charger 50 may have a coupling portion configuredto couple with the device. Additionally, in some embodiments, thecharger 50 may be coupled to more than one device 40, 40 b at a time.

The process may also proceed to step 1010, wherein the device 40 and thecharger 50 are placed on the wireless charger 82. At step 1010, thewireless charger 82 provides power to the charger 50. The charger 50 mayretain a portion of this power, as well as pass power to the mobiledevice 40. As described previously, in embodiments where the charger 50is charged while it is coupled to the device 40, there are a number ofschemes for how the charger 50 stores or transfers power. For example,in some embodiments, the charger 50 may store power until it reaches 50%of its battery capacity, after which the charger 50 wirelessly transferspower to the device 40. This is merely but one example, and a number ofcharging schemes may be used when the charger 50 is charging whilecoupled to the device 40.

Various embodiments of the invention may be implemented at least in partin any conventional computer programming language. For example, someembodiments may be implemented in a procedural programming language(e.g., “C”), or in an object oriented programming language (e.g.,“C++”). Other embodiments of the invention may be implemented aspreprogrammed hardware elements (e.g., application specific integratedcircuits, FPGAs, and digital signal processors), or other relatedcomponents.

In an alternative embodiment, the disclosed apparatus and methods (e.g.,see the various flow charts described above) may be implemented as acomputer program product for use with a computer system. Suchimplementation may include a series of computer instructions fixedeither on a tangible, non-transitory medium, such as a computer readablemedium (e.g., a diskette, CD-ROM, ROM, NVM, flash-memory, or fixeddisk). The series of computer instructions can embody all or part of thefunctionality previously described herein with respect to the system.

Those skilled in the art should appreciate that such computerinstructions can be written in a number of programming languages for usewith many computer architectures or operating systems. Furthermore, suchinstructions may be stored in any memory device, such as semiconductor,magnetic, optical or other memory devices, and may be transmitted usingany communications technology, such as optical, infrared, microwave, orother transmission technologies.

Among other ways, such a computer program product may be distributed asa removable medium with accompanying printed or electronic documentation(e.g., shrink wrapped software), preloaded with a computer system (e.g.,on system ROM or fixed disk), or distributed from a server or electronicbulletin board over the network (e.g., the Internet or World Wide Web).In fact, some embodiments may be implemented in a software-as-a-servicemodel (“SAAS”) or cloud computing model. Of course, some embodiments ofthe invention may be implemented as a combination of both software(e.g., a computer program product) and hardware. Still other embodimentsof the invention are implemented as entirely hardware, or entirelysoftware.

Disclosed embodiments, or portions thereof, may be combined in ways notlisted above and/or not explicitly claimed. In addition, embodimentsdisclosed herein may be suitably practiced, absent any element that isnot specifically disclosed herein. Accordingly, the invention should notbe viewed as being limited to the disclosed embodiments.

The embodiments of the invention described above are intended to bemerely exemplary; numerous variations and modifications will be apparentto those skilled in the art. Such variations and modifications areintended to be within the scope of the present invention as defined byany of the appended claims.

What is claimed is:
 1. A method of wirelessly charging a smartphonedevice, the method comprising: providing a smartphone device having asmartphone antenna configured to receive power wirelessly; providing acharging device having: a battery having a front surface and a backsurface, an antenna closer to the front surface than the back surface,the antenna comprising a wireless power transmit antenna or a dual-modeantenna, the antenna configured to wirelessly transmit power, a housingsurrounding the battery and the first antenna, the housing having afront contact surface and a rear surface, a coupling portion configuredto couple the charging device with the smartphone device, the couplingportion being closer to the front contact surface than the rear surface,wherein the antenna is closer to the contact surface than the rearsurface; charging the smartphone device by positioning the chargingdevice relative to the smartphone device such that the antenna transmitspower to the smartphone antenna.
 2. The method as defined by claim 1,wherein positioning the charging device relative to the smartphonedevice comprises coupling the charging device to the smartphone device.3. The method as defined by claim 2, wherein the positioningsubstantially aligns the antenna with the smartphone antenna.
 4. Themethod as defined by claim 1, wherein the charging device includes asecond antenna closer to the back surface than the front surface, thesecond antenna comprising a wireless power receiver antenna or adual-mode antenna, the second antenna configured to wirelessly receivepower, wherein the second antenna is surrounded by the housing.
 5. Themethod as defined by claim 1, further comprising uncoupling the chargingdevice from the smartphone device.
 6. The method as defined by claim 1,further comprising simultaneously charging the charging device from agrid-connected charger as the charging device charges the smartphonedevice.
 7. The method as defined by claim 4, further comprisingsimultaneously charging a second electronic device having a seconddevice antenna by positioning the charging device relative to the secondelectronic device such that the second antenna transmits power to thesecond device antenna.
 8. The method as defined by claim 1, wherein thecoupling portion comprises a magnet.
 9. A charging device for wirelesslycharging an electronic device having a wireless power receiver antenna,the charging device comprising: a battery having a front surface and aback surface; a first antenna comprising a wireless power transmitantenna or a dual-mode antenna, the first antenna configured towirelessly transmit power; a second antenna comprising a wireless powerreceiver antenna or a dual-mode antenna, the second antenna configuredto wirelessly receive power; a housing surrounding the battery, thefirst antenna, the second antenna, and a coupling portion, the housinghaving a front contact surface and a rear surface, the coupling portionconfigured to couple the charging device with the electronic device, thecoupling portion being closer to the contact surface than the rearsurface, the first antenna being closer to the contact surface than therear surface, and the second antenna being closer to the rear surfacethan the contact surface, the battery being disposed between the firstantenna and the second antenna.
 10. The charging device as defined byclaim 9, wherein the rear surface is configured to couple with a secondelectronic device.
 11. The charging device as defined by claim 9,wherein the charging device includes an electromechanical connection forreceiving power.
 12. The charging device as defined by claim 9, whereinthe device has a tapered transition surface between the contact surfaceand the rear surface.
 13. The charging device as defined by claim 9,further comprising a heat pipe coupled with the battery.
 14. Thecharging device as defined by claim 9, wherein the coupling portionincludes an adhesive, magnet, suction cup, and/or hook and loopfasteners.
 15. The charging device as defined by claim 14, wherein thehousing is imperforate.
 16. The charging device as defined by claim 9,wherein the first antenna is also configured to receive powerwirelessly.
 17. The charging device as defined by claim 9, wherein thesecond antenna is also configured to transmit power wirelessly.
 18. Asystem comprising: a smartphone having a smartphone battery, thesmartphone also having a smartphone antenna configured to receive powerwirelessly, the smartphone battery and the smartphone antenna beingwithin a smartphone housing, the smartphone housing having a smartphonesurface nearest to the smartphone antenna; a charging device having: adevice battery having a front surface and a back surface, a frontantenna closer to the front surface than the back surface of the devicebattery, the front antenna comprising a wireless power transmit antennaor a dual-mode antenna, the front antenna configured to wirelesslytransmit power, a charging device housing surrounding the device batteryand the front antenna, the charging device housing having a frontcontact surface and a rear surface, and a smartphone coupling portioncloser to the front contact surface than the rear surface of thehousing, the smartphone coupling portion configured to couple thecharging device with the smartphone, wherein the front antenna is closerto the front contact surface than the rear surface.
 19. The system ofclaim 18, further comprising: a back antenna nearest to the backsurface, the back antenna comprising a wireless power receiver antennaor a dual-mode antenna, the back antenna configured to wirelesslyreceive power, the charging device housing also surrounding the backantenna, and the back antenna being closer to the rear surface than thefront contact surface.
 20. The system of claim 18, wherein the couplingportion includes a magnet.
 21. The system of claim 18, wherein thesmartphone has a corresponding coupling portion configured to couplewith the coupling portion of the charging device.
 22. The system ofclaim 21, wherein the corresponding coupling portion comprises amagnetically attractive portion.